Known, prior art inhalation devices include, for example, those shown in U.S. Pat. Nos. 3,938,516; 3,964,483; 3,973,566; and 4,005,711. In all of these devices, a container containing a powdered medicament is inserted into an opening in the device and held by either a friction fit or by the finger pressure of the user. It is sometimes difficult, however, to properly insert, retain and/or withdraw the container (hereinafter generally referred to as the capsule). For example, if the capsule is too small it is not properly retained within the opening, or if it is too big it may be damaged or crushed on insertion. The use of such devices requires that the capsule first be opened (which requires both hands) and then inserted into the opening in the device (also requiring both hands). Thus the device is set down when the capsule is opened and then picked up for placement of the capsule in the opening. This procedure increases the chances of spillage of the powdered medicament.
Other devices have been proposed which employ means for opening the capsule after it is inserted into the inhalation device. See, for example U.S. Pat. No. 4,014,336. However, with these devices there is a possibility that that portion of the capsule removed might remain in the device and adversely affect the delivery of the medicament.
Still other devices are discussed in U.S. Pat. Nos. 1,406,903; 2,587,215; and 2,603,215.
With the instant invention, the chance of accidental spillage is lessened because the capsule is first positioned on the device, and then the top half or cap of the capsule is removed. Further, when properly used, no portion of the capsule will adversely affect delivery of the medicament during inhalation.